1. The Field of the Invention
This invention relates to the field of electrosurgical instruments, systems, and methods. More particularly, the invention relates to electrosurgical systems, instruments, and methods that facilitate delivery of wireless signals to an electrosurgical generator to initiate delivery of electrosurgical energy to an electrosurgical instrument.
2. The Relevant Technology
As is known to those skilled in the art, modern surgical techniques typically employ radio frequency (RF) power to cut tissue and coagulate bleeding encountered in performing surgical procedures. For historical perspective and details of such techniques, reference is made to U.S. Pat. No. 4,936,842, issued to D'Amelio et al., and entitled “Electroprobe Apparatus,” the disclosure of which is incorporated by this reference.
As is known to those skilled in the medical arts, electrosurgery is widely used and offers many advantages including the use of a single surgical instrument for both cutting and coagulation. Every monopolar electrosurgical generator system has an active electrode, such as in the form of an electrosurgical instrument having a hand piece and a conductive electrode or tip, which is applied by the surgeon to the patient at the surgical site to perform surgery and a return electrode to connect the patient back to the generator.
The electrode or tip of the electrosurgical instrument is small at the point of contact with the patient to produce a high current density in order to produce a surgical effect of cutting or coagulating tissue. The return electrode carries the same current provided to the electrode or tip of the electrosurgical instrument and back to the electrosurgical generator. Consequently, the return electrode must be large enough in effective surface area at the point of communication with the patient such that a low density current flows from the patient to the return electrode. In the event that a relatively high current density is produced at the return electrode, the temperature of the patient's skin and tissue will rise in this area and may result in an undesirable patient burn.
To make the electrical connection between the electrosurgical generator and the electrosurgical instrument a cord, having an electrically conductive core, extends from the electrosurgical generator to the electrosurgical instrument. The cord has certain flexibility and weight characteristics that limit the ability of the physician during a surgical procedure. For example, the cord has a defined length that limits the range of motion provided to the physician using the active electrode. Additionally, having an elongated cord in an operating environment to provide the physician with greater range of motion may also cause problems. For instance, the cord may become wrapped around medical equipment and/or may tangle or trip the physician or other medical personnel. Consequently, use of an elongated electrical cord may be dangerous to the physician and other medical personnel in the operating environment.
In addition to the above, the weight of the cord electrically linking the generator and the active electrode limits the physician's ability to continually hold and use the active electrode. The weight of the cord continually pulls the end of the electrosurgical instrument to which it is attached. During use, therefore, the physician may become fatigued during a surgical procedure that requires extensive and continual use of the electrosurgical instrument.
Additionally, the flexibility of the cord linking the generator and the active electrode limits the effectiveness of the electrosurgical instrument. Each cord has a conductive core with insulation surrounding the same. During manufacture of the cord, certain physical characteristics and properties become associated with the cord. For instance, the combination of core and insulation define an initial orientation of the cord. This initial orientation may be changed as a physician, clinician or operator manipulates the electrosurgical instrument and moves the cord. Although moved to a new position, the core and insulation have a “memory” of the initial orientation and attempt to return to the initial orientation upon the physician, clinician, or operator releasing the tension or force applied to the cord. The force applied by the core and insulation to return the cord to the initial orientation limits the movement of the physician, clinician, or operator. More specifically, the physician, clinician, or operator of the electrosurgical instrument must continually overcome the force applied by the cord to return the cord to the initial orientation. Resultantly, the physician, clinician, or operator may become fatigued and may loose range of motion of the electrosurgical instrument.
Further, the “memory” associated with the cord may move the electrosurgical instrument from within the sterile field upon resting the electrosurgical instrument upon a table or other surface within the sterile field. For instance, as the cord moves to return to the initial orientation, the force applied by the cord upon the electrosurgical instrument may result in the instrument being moved out of the sterile field. This results in a time delay in the procedure as replacement instruments are retrieved and positioned for use.